Automobile drag coefficient
The drag coefficient is a common measure in automotive design as it pertains to aerodynamics. Drag is a force that acts parallel to and in the same direction as the airflow. The drag coefficient of an automobile measures the way the automobile passes through the surrounding air. When automobile companies design a new vehicle they take into consideration the automobile drag coefficient in addition to the other performance characteristics. Aerodynamic drag increases with the square of speed; therefore it becomes critically important at higher speeds. Reducing the drag coefficient in an automobile improves the performance of the vehicle as it pertains to speed and fuel efficiency. There are many different ways to reduce the drag of a vehicle. A common way to measure the drag of the vehicle is through the drag area.
The reduction of drag in road vehicles has led to increases in the top speed of the vehicle and the vehicle's fuel efficiency, as well as many other performance characteristics, such as handling and acceleration. The two main factors that impact drag are the frontal area of the vehicle and the drag coefficient. The drag coefficient is a unit-less value that denotes how much an object resists movement through a fluid such as water or air. A potential complication of altering a vehicle's aerodynamics is that it may cause the vehicle to get too much lift. Lift is an aerodynamic force that acts perpendicular to the airflow around the body of the vehicle. Too much lift can cause the vehicle to lose road traction which can be very unsafe. Lowering the drag coefficient comes from streamlining the exterior body of the vehicle. Streamlining the body requires assumptions about the surrounding airspeed and characteristic use of the vehicle.
The deletion of parts on a vehicle is an easy way for designers and vehicle owners to reduce parasitic and frontal drag of the vehicle with little cost and effort. Deletion can be as simple as removing an aftermarket part, or part that has been installed on the vehicle after production, or having to modify and remove an OEM part, meaning any part of the vehicle that was originally manufactured on the vehicle. Most production sports cars and high efficiency vehicles come standard with many of these deletions in order to be competitive in the automotive and race market, while others choose to keep these drag-increasing aspects of the vehicle for their visual aspects, or to fit the typical uses of their customer base.
A roof rack is a common trait on many SUV and station wagon vehicles. While roof racks are very useful in carrying extra storage on a vehicle, they also increase the frontal area of the vehicle and increase the drag coefficient. This is because the air flows over the top of the vehicle, following the smooth lines of the hood and windshield, then collides with the roof rack and causes turbulence. The removal of this part has led to increases in fuel efficiency in several studies.
Mudflaps are now rarely specified as standard on production cars as they interfere with the clean airflow around the vehicle. For larger vehicles such as trucks, mud flaps are still important for their control of spray, and in 2010 a new version of the mud flap was introduced that has been shown to create significantly less aerodynamic drag than standard mud flaps.
A rear spoiler usually comes standard in most sports vehicles and resembles the shape of a raised wing in the rear of the vehicle. The main purpose of a rear spoiler in a vehicle's design is to counteract lift, thereby increasing stability at higher speeds. In order to achieve the lowest possible drag, air must flow around the streamlined body of the vehicle without coming into contact with any areas of possible turbulence. A rear spoiler design that stands off the rear deck lid will increase downforce, reducing lift at high speeds while incurring a drag penalty. Flat spoilers, possibly angled slightly downward may reduce turbulence and thereby reduce the coefficient of drag. Some cars now feature automatically adjustable rear spoilers, so at lower speed the effect on drag is reduced when the benefits of reduced lift are not required.
Side mirrors both increase the frontal area of the vehicle and increase the coefficient of drag since they protrude from the side of the vehicle. In order to decrease the impact that side mirrors have on the drag of the vehicle the side mirrors can be replaced with smaller mirrors or mirrors with a different shape. Several concept cars of the 2010s are replacing mirrors with tiny cameras but this option is not common for production cars because most countries require side mirrors.
While they do not have the biggest impact on the drag coefficient due to their small size, radio antennas commonly found protruding from the front of the vehicle can be relocated and changed in design to rid the car of this added drag. The most common replacement for the standard car antenna is the shark fin antenna found in most high efficiency vehicles.
The effect that windshield wipers have on a vehicle's airflow varies between vehicles; however, they are often omitted from race vehicles and high efficiency concepts in order to maintain the smallest possible coefficient of drag. A much more common option is to replace the windshield wipers with lower profile wipers, or to only remove the windshield wiper on the passenger side of the vehicle, and even to fabricate a deflector to deflect the air up and over the wipers.
Another alternative is to equip the vehicle with a single wiper placed in the centre of the windshield, allowing it to cover both sides of the windshield. This mitigates the amount of drag by decreasing the frontal area of the blade. While such application may be useful for racing, for most road vehicles this would produce minimal improvement in overall drag reduction.
The application of new parts and concepts onto the vehicle design are easier to include when in the design stage of a vehicle, rather than in aftermarket (automotive) parts, however, the fabrication of these parts assists in the streamlining of the vehicle and can help greatly reduce the drag of the vehicle. Most vehicles with very low drag coefficients, such as race cars and high efficiency concept cars, apply these ideas to their design.
When air flows around the wheel wells it gets disturbed by the rims of the vehicles and forms an area of turbulence around the wheel. In order for the air to flow more smoothly around the wheel well, smooth wheel covers are often applied. Smooth wheel covers are hub caps with no holes in them for air to pass through. This design reduces drag; however, it may cause the brakes to heat up more quickly because the covers prevent airflow around the brake system. As a result, this modification is more commonly seen in high efficiency vehicles rather than sports cars or racing vehicles.
Partial grille block
The front grille of a vehicle is used to direct air directly into the engine compartment. In a streamlined design the air flows around the vehicle rather than through; however, the grille of a vehicle redirects airflow from around the vehicle to through the vehicle, which then increases the drag. In order to reduce this impact a grille block is often used. A grille block covers up a portion of, or the entirety of, the front grille of a vehicle. In most high efficiency models or in vehicles with low drag coefficients, a very small grille will already be built into the vehicle's design, eliminating the need for a grille block. The grille in most production vehicles is generally designed to maximize air flow into the engine compartment to keep it from overheating. This design can actually create too much airflow into the engine compartment, preventing it from warming up in a timely manner, and in such cases a grille block is used to increase engine performance and reduce vehicle drag simultaneously.[page needed]
The underside of a vehicle often traps air in various places and adds turbulence around the vehicle. In most racing vehicles this is eliminated by covering the entire underside of the vehicle in what is called an under tray. This tray prevents any air from becoming trapped under the vehicle and reduces drag.
Fender skirts are often made as extensions of the body panels of the vehicles and cover the entire wheel wells. Much like smooth wheel covers this modification reduces the drag of the vehicle by preventing any air from becoming trapped in the wheel well and assists in streamlining the body of the vehicle. Fender skirts are more commonly found on the rear wheel wells of a vehicle because the tires do not turn and the design is much simpler. This is commonly seen in vehicles such as the first generation Honda Insight. Front fender skirts have the same effect on reducing drag as the rear wheel skirts, but must be further offset from the body in order to compensate for the tire sticking out from the body of the vehicle as turns are made.
Modified front bumper
The front bumper is the first part of the vehicle that the air must flow around. Therefore, it plays a crucial role in reducing drag. A front air dam is often used which extends from the very front of the vehicle down to the lowest part of the vehicle. This is done to direct airflow around and over the vehicle rather than allowing air to travel under it. Contoured deflectors, or tire spats, are often made as part of the front bumper in order to direct airflow around the tire without having any increase to the outward flow.
Boattails and Kammbacks
A boattail can greatly reduce a vehicle's total drag. Boattails create a teardrop shape that will give the vehicle a more streamlined profile, reducing the occurrence of drag inducing flow separation. A kammback is a truncated boattail. It is created as an extension of the rear of the vehicle, moving the rear backward at a slight angle toward the bumper of the car. This can reduce drag as well but a boattail would reduce the vehicles drag more. Nonetheless, for practical and style reasons, a kammback is more commonly seen in racing, high efficiency vehicles, and trucking.
Typical drag coefficients
The average modern automobile achieves a drag coefficient of between 0.25 and 0.3. SUVs, with their typically boxy shapes, typically achieve a Cd=0.35–0.45. The drag coefficient of a vehicle is affected by the shape of body of the vehicle. Various other characteristics affect the coefficient of drag as well, and are taken into account in these examples. Some sports cars have a surprisingly high drag coefficient (Such as the Ariel Atom at 0.40), but this is to compensate for the amount of lift the vehicle generates, while others use aerodynamics to their advantage to gain speed and as a result have much lower drag coefficients.
Some examples of Cd follow. Figures given are generally for the basic model, which may not be available in some markets. Some "high performance" models may actually have higher drag, due to wider tires, extra spoilers and larger cooling systems as many basic/low power models have half size radiators with the remaining area blanked off to reduce cooling and engine bay drag.
The Cd of a given vehicle will vary depending on which wind tunnel it is measured in. Variations of up to 5% have been documented and variations in test technique and analysis can also make a difference. So if the same vehicle with a drag coefficient of Cd=0.30 was measured in a different tunnel it could be anywhere from Cd=0.285 to Cd=0.315.
While designers pay attention to the overall shape of the automobile, they also bear in mind that reducing the frontal area of the shape helps reduce the drag. The product of drag coefficient and area - drag area - is represented as CdA (or CxA), a multiplication of the Cd value by the area.
The term drag area derives from aerodynamics, where it is the product of some reference area (such as cross-sectional area, total surface area, or similar) and the drag coefficient. In 2003, Car and Driver magazine adopted this metric as a more intuitive way to compare the aerodynamic efficiency of various automobiles.
The force required to overcome drag is: Therefore: Where the drag coefficient and reference area have been collapsed into the drag area term. This allows direct estimation of the drag force at a given speed for any vehicle for which only the drag area is known and therefore easier comparison.
As drag area CdA is the fundamental value that determines power required for a given cruise speed it is a critical parameter for fuel consumption at a steady speed. This relation also allows an estimation of the new top speed of a car with a tuned engine,
Or the power required for a target top speed,
Average full-size passenger cars have a drag area of roughly 8.50 sq ft (0.790 m2). Reported drag areas range from the 1999 Honda Insight at 5.1 sq ft (0.47 m2) to the 2003 Hummer H2 at 26.5 sq ft (2.46 m2). The drag area of a bicycle (and rider) is also in the range of 6.5–7.5 sq ft (0.60–0.70 m2).
- North American market
- 0.30 with range extender
- European market
- Wang, Brian (2009-03-16). "Reducing Drag on Cars and Trucks by 15-18%". Next Big Future. Archived from the original on 2018-01-29. Retrieved 2018-01-28.
- Turner, Mike. "Aerocivic - Honda Civic modifications for maximum gas mileage -". aerocivic. Retrieved 2018-01-28.
- Guinn, Wayne D. "Camaro Spoiler Equipment". Camaro - Untold Secrets. US. Archived from the original on 2000-05-19.
- Davis, Marlan (February 2009). "Aerodynamic Tips and Tricks You Can Use for Better Performance". Hot Rod Magazine. US. Archived from the original on 2012-04-22.
- "Mini-experiment: the wrath of roof racks". MetroMPG. US. 2007-03-07. Retrieved 2018-11-13.
- Dragani, Rachelle (2013-08-04). "These Mud Flaps Can Help Trucks Slash Fuel Costs". Popular Mechanics. US. Retrieved 2020-01-14.
- Physics for Scientists and Engineers, p. 448, at Google Books
- "Reflections on side mirrors: testing drag vs. MPG". MetroMPG.com. 2006-08-31. Retrieved 2018-12-07.
- The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains, Volume 1, p. 490, at Google Books
- "First drive review: Porsche Panamera Sport Turismo". Autocar. 2012-12-07. Retrieved 2013-03-01.
- "Estimation of The Drag of a Roof Mounted Antenna (AU Ford Falcon)". Virtual V8. Australia. September 2005. Retrieved 2019-03-03.
- "What is an Air Deflector?". wiseGEEK. US. Retrieved 2019-03-03.
- Browand, Fred (2005-10-10). "Reducing Aerodynamic Drag and Fuel Consumption" (PDF). US: Stanford University. Retrieved 2019-03-03.
- Ali, Hussain. "Drag Reduction on a Production Vehicle" (PDF). UK: Coventry University.[dead link]
- Bridger, Gabriel (2010-12-13). "The 1M's Air Curtain in Detail". BimmerFile. Retrieved 2018-02-10.
- "How Air Curtains on F-150 Help Reduce Aerodynamic Drag and Aid Fuel Efficiency" (Press release). 2015-07-15. Retrieved 2018-02-10.
- "Designing for design's sake—with aerodynamics built in" (Press release). Honda. Archived from the original on 2018-02-20. Retrieved 2018-02-20.
- Korff, Walter Henry (1980). Designing tomorrow's cars: from concept, step-by-step, to detail design. M-C Publications. ISBN 9780960385003.
- Popular Mechanics Sep 1981, p. 158, at Google Books
- Lögdberg, Ola (2008). "Turbulent Boundary Layer Separation and Control". Stockholm: KTH Royal Institute of Technology. Retrieved 2019-03-03.
- Hoyt, Wade (October 1985). "Shaping up tomorrow's cars". Popular Mechanics: 131.
- König, Wolfgang (2008-04-22). "Die Tops und Flops im Windkanal". Auto Bild (in German). Axel Springer. Retrieved 2019-09-10.
- "Technique of the VW Beetle". Maggiolinoweb.it. Retrieved 2009-10-24.
- "The Mayfield Homepage - Coefficient of Drag for Selected Vehicles". Mayfco.com. Retrieved 2009-10-24.
- "Volkswagen Cabriolet MK1 Specs". Cabby-Info.com. Archived from the original on 2010-02-05. Retrieved 2010-01-12.
- "Lancia Aprilia Tipo 97 technical specifications". carfolio.com. Retrieved 2012-03-13.
- "Lincoln Town Car technical data". automobile-catalog.com. Retrieved 2018-09-14.
- Visnic, Bill (2017-12-18). "Level Zero hero". SAE International. Archived from the original on 2019-05-29. Retrieved 2019-05-29.
- "Report on 2nd generation Grand Marquis updates". nwitimes.com. 2018-02-16. Retrieved 2018-09-14.
- "1998 SUBARU FORESTER S". theautochannel.com. Retrieved 2010-05-02.
- "Chevrolet Astro Van (1996)". theautochannel.com. Retrieved 2010-05-02.
- "2002 Ariel Atom Specifications". getcarspecs.com. Retrieved 2012-10-12.
- "1995 Ford Aerostar Specs". motortrend.com. Retrieved 2010-08-18.
- "1981 Ford Escort". carfolio.com. Retrieved 2010-05-02.
- "2016 Tacoma Product Information" (Press release). US: Toyota. 2015. Retrieved 2019-05-19.
- "Lincoln Mark VII technical data". automobile-catalog.com. Retrieved 2018-09-14.
- "Subaru Forester specs available". CarsDirect. Retrieved 2009-10-24.
- "Evworld Feature: Giving The New Beetle Wings:Vw | Rogers | Beetle | Wing | Drag | Porsche | Volkswagen | Thiokol | Utah | Fuel | Economy | Biodiesel | Diesel | Aerodynamics". Evworld.com. Retrieved 2010-12-07.
- "Aero Testing - Part 3". AutoSpeed. Archived from the original on 2009-11-21. Retrieved 2009-10-24.
- "Mercury Grand Marquis technical data". automobile-catalog.com. Retrieved 2018-09-14.
- "Mercury Grand Marquis technical data". automobile-catalog.com. Retrieved 2018-09-14.
- Daily Mail Motor Review 1984
- "Ecomodder Wiki Vehicle Coefficient of Drag". Archived from the original on 2010-04-25. Retrieved 2010-05-02.
- "Lincoln Town Car technical data". automobile-catalog.com. Retrieved 2018-09-14.
- "Subaru Canada". Subaru.ca. Retrieved 2009-10-24.
- Ralf J. F. Kieselbach, Stromlinienautos in Europa und USA, Kohlhammer Verlag, Stuttgart 1982, page 19
- "Toyota Celica GT (1995)". theautochannel.com. Archived from the original on 2010-04-12. Retrieved 2010-05-02.
- Smith, David C. (December 1984). "Golf, Jetta much improved and, with them, VWA's hopes". Ward's Auto World.
- "All-new 2019 Ram 1500 – No Compromise Truck, Leading in Durability, Technology and Efficiency" (Press release). FCA North America. 2018-01-15. Retrieved 2019-09-22.
- "Archived copy". Archived from the original on 2012-07-21. Retrieved 2012-07-28.CS1 maint: archived copy as title (link) Data as published on the Team website after 2012 Le Mans Race after the addition of rear view mirrors
- "Ford Windstar 1st gen technical data". automobile-catalog.com. Retrieved 2018-09-14.
- "Ford Windstar 2nd gen technical data". automobile-catalog.com. Retrieved 2018-09-14.
- "2002 Renault Clio II 1.5 dCi 80 technical specifications and data - 3 door 1.5 litre (1461 cc) S4 79.1 PS - Carfolio.com car specifications pages". Carfolio.com. Retrieved 2009-10-24.
- Ramsey, Jonathon (2009-03-26). "Tesla Model S: Kč970.000 (Kč970.000 (Kč970.000 ($50,000))) EV sedan seats seven, 300-mile range, 0-60 in 5.5s". autobloggreen. Archived from the original on 2009-03-27. Retrieved 2009-04-12.
- "Leichtbau ist nicht das Wichtigste" (in German). Auto, Motor und Sport.
Da der Smart aufgrund seiner großen Frontfläche von 2,06 m2 einen hohen cW-Wert von 0,35 hat, verbraucht er im Vergleich zum niedrigen Gewicht vergleichsweise viel.
- "Toyota Previa LE S/C 1995". theautochannel.com. Archived from the original on 2010-05-06. Retrieved 2010-05-02.
- "1990 Toyota Previa". carfolio.com. Retrieved 2010-05-02.
- "1982 Toyota Celica Supra" (Press release). US: Toyota. 1981. Archived from the original on 2016-01-21. Retrieved 2018-05-26.
- "Nissan Altima GXE (1995)". theautochannel.com. Archived from the original on 2010-05-24. Retrieved 2010-05-02.
- "2002 Nissan Skyline R34 - R34 vs R35". importtuner.com. 2009-10-01. Retrieved 2014-10-01.
- "The Aerodynamics of the Saab Automobiles". Saab History. 2007-04-01. Retrieved 2016-08-05.
- "Saturn SL2 (1995)". theautochannel.com. Archived from the original on 2010-03-28. Retrieved 2010-05-02.
- "Subaru Canada". Subaru.ca. Retrieved 2009-10-24.
- "1995 SUBARU LEGACY L WAGON". theautochannel.com. Retrieved 2010-05-02.
- "1996 Toyota Corolla DX Wagon". theautochannel.com. Archived from the original on 1996-11-28. Retrieved 2010-05-02.
- "Aerodynamics". Le Double Chevron (#59). 1980.
- "Acura Integra GS-R (1994)". theautochannel.com. Retrieved 2010-05-02.
- "2004 Acura RSX Coupe Specs". automobilemag.com. Archived from the original on 2014-10-06. Retrieved 2014-10-01.
- "1964 Giulia 1600 Series 105". conceptcarz.com. Retrieved 2011-06-28.
- "Ford Escort ZX2 (1998)". theautochannel.com. Archived from the original on 2010-06-04. Retrieved 2010-05-02.
- "Ford Fusion specs available". CarsDirect. Retrieved 2009-10-24.
- "1995 NISSAN 200SX SE-R TWO-DOOR COUPE". motortrend.com. Retrieved 2010-05-02.
- "Saturn SL2 (1999)". theautochannel.com. Retrieved 2010-05-02.
- Paul, Rik (1996-10-02). "1997 Toyota Camry Road Test". Motor Trend. Retrieved 2018-12-04.
- "1990 Chevrolet Corsica Sales training Video". youtube.com. Retrieved 2011-01-15.
- "Review:2003 Toyota Matrix". theautochannel.com. Retrieved 2010-05-02.
- "1994 FORD TAURUS GL". theautochannel.com. Retrieved 2010-05-02.[dead link]
- "Honda Civic DX Hatchback (1996)". theautochannel.com. Retrieved 2010-05-02.
- "Honda Civic EX Sedan (1996)". theautochannel.com. Retrieved 2010-05-02.
- "1995 NISSAN 240SX SE SPORT COUPE". motortrend.com. Retrieved 2010-05-02.
- "Nissan Altima GLE (1998)". theautochannel.com. Archived from the original on 2010-04-20. Retrieved 2010-05-02.
- Karel Rosenkranz, Tatra, Autoalbum 2002, page 107
- "Toyota Celica GT-S (2000)". theautochannel.com. Retrieved 2010-05-02.
- "Toyota Tercel DX (1995)". theautochannel.com. Retrieved 2010-05-02.
- "2019 Corolla Hatchback eBrochure" (PDF). US: Toyota. p. 22. Archived from the original (PDF) on 2019-05-17. Retrieved 2019-05-17.
- "Saturn SL1 (1996)". theautochannel.com. Retrieved 2010-05-02.[dead link]
- "fiatcoupehistory". Archived from the original on 2009-08-04.
- "Toyota Tercel Reference - CdA List". Archived from the original on 2011-07-16. Retrieved 2010-07-15.
- "2011 Infiniti G Coupe Specifications". Infiniti USA. Archived from the original on 2010-12-05. Retrieved 2011-01-25.
- "2001 Kia Rio Specifications - View New Kia Rio 2001 Specs & Data at". Internetautoguide.com. Archived from the original on 2010-07-26. Retrieved 2010-04-23.
- "2010 Mazda 2 II (DE, facelift 2010) 1.5i (102 Hp) Automatic | Technical specs, data, fuel consumption, Dimensions". www.auto-data.net. Retrieved 2020-06-21.
- "TG meets the Pagani Huayra - BBC Top Gear". Topgear.com. 2012-06-08. Retrieved 2013-04-05.
- "1998 TOYOTA COROLLA LE". theautochannel.com. Retrieved 2010-05-02.
- "Corolla" (Press release). UK: Toyota. February 2019. Retrieved 2019-02-14.
- "Toyota Paseo (1996)". theautochannel.com. Retrieved 2010-05-02.
- "2017 Chevy Bolt EV Is Less of a Drag Than Originally Believed". Retrieved 2017-03-29.
- "Carfolio Car Specifications". Retrieved 2010-05-02.
- "Lotus Elan+2". Lotus. 1967 – via LotusElan.net.
- "Four of a Kind: The Alfa Romeo 164 and the "Type Four" Cars". ateupwithmotor.com. Archived from the original on 2011-07-07. Retrieved 2011-06-28.
- "The new BMW 3 Series Sedan" (Press release).
- "1996/1997 FORD TAURUS SHO". theautochannel.com. Retrieved 2010-05-02.
- "1996 FORD TAURUS GL SEDAN". theautochannel.com. Retrieved 2010-05-02.
- gtmash. "Honda Civic CRX - Car Cutaway - Modern Racer - Features". Modern Racer. Retrieved 2009-10-24.
- "2009 Nissan 370Z Coupe Specs". Nissan USA. 2009-08-31. Archived from the original on 2010-02-08. Retrieved 2009-10-24.
- "Vehicle Coefficient of Drag List - EcoModder". ecomodder.com. Retrieved 2017-12-09.
- "2003 Toyota Corolla Specs". motortrend.com. Retrieved 2010-05-02.
- "The New Corolla Model Range" (PDF) (Press release). Toyota Motor Europe. February 2019. Retrieved 2019-05-17.
- Sherman, Don (June 2014). "Five slippery cars enter a wind tunnel; one slinks out a winner" (PDF) (Press release). US: Tesla. Retrieved 2019-03-03.
- Voss, Arv. "Chevy's new Impala provides a breath of fresh air". SFGate. Retrieved 2018-02-09.
- "Meet the Focus". Archived from the original on 2018-02-26.
- "1992 Alfa Romeo 155 1.8 Twin Spark technical specifications". carfolio.com. Retrieved 2011-06-28.
- "The BMW i3" (Press release). BMW. 2013. Retrieved 2018-05-24.
- "Mini wind tunnel fine-tunes GM designs". Automotive News. 2015-11-30. Retrieved 2018-12-16.
- "Fiat Tipo - Al lancio le Opening Edition benzina e diesel". Quattroruote (in Italian). Italy. 2015-11-28. Retrieved 2016-12-27.
- "Ford Escape Hybrid". All-about-car-selection.com. Archived from the original on 2011-07-07. Retrieved 2010-04-23.
- "All-new Ford Focus C-Max - Ford Forums - Mustang Forum, Ford Trucks and Cars". Ford Forums. Retrieved 2010-04-23.
- "Vehicle Specifications 2005 Honda Accord Hybrid". Honda Owners Site. Retrieved 2019-03-03.
- "Kia Niro Exterior". Kia Motors. Retrieved 2017-11-20.
- Long, Brian (2000). Lexus: The Challenge to Create the Finest Automobile. Cardiff: Veloce Publishing. pp. 19–20. ISBN 1-901295-81-8.
- "2010 Mazda3 Specification Deck" (PDF). Mazda Motor of America, Inc. 2009-03-24. Retrieved 2018-11-25.
- "Nissan Leaf Zero Emission" (PDF) (Press release). UK: Nissan. 2013-07-01. Retrieved 2016-02-25.[permanent dead link]
- "2014 Toyota Corolla Product Information" (Press release). US: Toyota. 2013-08-27. Retrieved 2018-12-07.
- "2020 Corolla eBrochure". US: Toyota. p. 25. Archived from the original on 2019-05-17. Retrieved 2019-05-17.
- "2000 Toyota Echo Review". theautochannel.com. Retrieved 2010-05-02.
- "Toyota Echo 4-Door (2000)". theautochannel.com. Retrieved 2010-05-02.
- "Dream Machines Number 39 – Volvo C70" (PDF). Sweden: Volvo. Retrieved 2018-11-11 – via Volvo Club UK.
- "Chrysler Concorde Specifications - Dimensions". US: Chrysler. Archived from the original on 2001-01-10. Retrieved 2018-12-31.
- Tan, Danny (21 July 2016). "Perodua Bezza officially launched – first ever sedan, 1.0 VVT-i and 1.3 Dual VVT-i, RM37k to RM51k EEV". Malaysia: paultan.org. Retrieved 2019-06-29. Cite magazine requires
- "2006 Chevrolet Corvette" (Press release). US: General Motors. 2005. Retrieved 2018-07-05.
- "The All-new 2013 Dodge Dart Redefines Performance" (Press release). FCA US. 2012-09-01. Retrieved 2019-07-05.
- "New Astra Price/Specification Guide" (PDF). UK: Vauxhall. p. 23. Archived from the original (PDF) on 2019-03-02. Retrieved 2019-03-02.
- Hutton, Ray (July 2000). "Audi A2". Car and Driver. Retrieved 2018-12-16.
- "New FIAT Croma in UK" (Press release). Fiat Auto (UK) Limited. 2005-08-01. Retrieved 2018-12-16.
- Csere, Csaba (May 2002). "2003 Honda Civic Hybrid". Car and Driver. Retrieved 2018-12-16.
- "All-New Honda Insight Hybrid Vehicle Introduced in Japan" (Press release). Tokyo, Japan: Honda Motor Co. 2009-02-05. Retrieved 2019-01-09.
- Markus, Frank (2010-11-15). "First Look: 2011 Hyundai Elantra - Motor Trend". Motor Trend. Motor Trend Group, LLC. Retrieved 2018-12-16.
- Walton, Chris (2010-08-20). "2011 Hyundai Sonata Hybrid Road Test". Edmunds. Retrieved 2018-12-16.
- "Archived copy". Archived from the original on 2006-04-08. Retrieved 2006-04-08.CS1 maint: archived copy as title (link)
- "Archived copy". Archived from the original on 2014-06-09. Retrieved 2014-06-09.CS1 maint: archived copy as title (link)
- "Special Report: Imports '87". Popular Mechanics. February 1987. p. 126.
- Hucho, edited by Wolf-Heinrich (1986). Aerodynamics of road vehicles : from fluid mechanics to vehicle engineering. London: Butterworths. p. 39. ISBN 978-0-408-01422-9.CS1 maint: extra text: authors list (link)
- Schütz, Thomas. Hucho - Aerodynamik des Automobils: Strömungsmechanik, Wärmetechnik, Fahrdynamik, Komfort. Springer-Verlag. ISBN 978-3-8348-1919-2.
- Winfield, Barry (March 2006). "2007 Toyota Camry SE" (PDF). Car and Driver. Hearst Magazine Media. Archived from the original (PDF) on 2015-06-08. Retrieved 2019-01-09.
- "2017 Toyota Camry Product Information Sheet" (Press release). Archived from the original on 2019-01-09. Retrieved 2019-01-09.
- Nate Martinez. "First Test:2013 Ford Fusion". motortrend.com. Retrieved 2014-05-28.
- "Ford Unveils All-New Focus" (PDF) (Press release). The Ford Motor Company. 2018-04-10. Retrieved 2018-04-11.
- "All-New 2017 Hyundai Elantra Brings Advanced Technology and Premium Convenience to the Compact Car Segment" (Press release). Imperial Beach, California: Hyundai Motor America. 2016-01-26. Retrieved 2018-12-18.
- "New 2020 Hyundai Sonata Makes Its North American Debut at the New York International Auto Show" (Press release). New York City. 2019-04-17. Retrieved 2019-07-05.
- "Mazda6" (PDF) (Press release) (in German). Germany: Mazda. Archived from the original (PDF) on 2009-01-20.
- "Mercedes-Benz S-Class, W 220 series (1998 to 2005)".
- Edward Loh (2011-12-02). "First Drive:2013 Subaru BRZ". Motortrend.com. Retrieved 2013-04-04.
- "Attainable Premium, Actualized: All-New 2019 Toyota Avalon Beams Effortless Sophistication, Style, and Exhilaration at the 2018 North American International Auto Show | Toyota" (Press release). 2018-01-15. Retrieved 2018-02-08.
- > "The new Jetta - world premiere - North American International Auto Show" (Press release).
- Interone Worldwide GmbH (2008-06-17). "BMW 3 Series Sedan : Technical data". Bmw.com. Archived from the original on 2009-10-13. Retrieved 2009-10-24.
- "Jaguar XE (2015) technical details and prices confirmed". Car. 2014-10-01. Retrieved 2014-10-15.
- "Mazda Launches Second SKYACTIV Model in Japan: Facelifted Axela".
- "Instantly thrilling: The new Mercedes-Benz C-Class Coupé". Mercedes. 2015-08-13. Archived from the original on 2016-03-04.
- "2019 Nissan Altima Press Kit" (Press release). US: Nissan. 2018-03-28. Retrieved 2018-06-22.
- "All-new Nissan Sylphy unveiled at Auto Shanghai 2019" (Press release). Shanghai: Nissan. 2019-04-15. Retrieved 2019-04-05.
- "SUV Coupé for the e-tron Family: The Audi e-tron Sportback" (Press release). 2019-11-20.
- Sherman, Don. "Drag Queens: Aerodynamics Compared" (PDF). Car and Driver (June 2014). Hearst Communications. Retrieved 2017-12-29.
- "2010 Toyota Prius Product Information | Toyota". Retrieved 2017-10-09.
- ""Aerodynamics: The best value of all current Porsche models"" (Press release). 2019-09-04. Retrieved 2019-10-14.
- "Vehicle Coefficient of Drag List". EcoModder. Retrieved 2017-11-16.
- "Model X Tesla Motors". Teslamotors.com. Retrieved 2018-02-13.
- "Technical Data" (Press release). Škoda. 2020-03-16. Retrieved 2020-04-22.
- "2017 Hyundai Ioniq Hybrid and Electric Models Soon to Be Available to U.S. Consumers" (Press release). Hyundai Motor America. 2017-02-14. Retrieved 2018-01-30.
- "All-New Kia Optima Hybrid Unveiled At 2016 Chicago Auto Show" (Press release). Kia Motors America. 2016-02-11. Retrieved 2018-02-08.
- "Die technischen Daten der S-Klasse Limousine" (PDF). Archived from the original (PDF) on 2018-11-11. Retrieved 2018-11-11.
- "C-Class awarded Environmental Certificate" (Press release). Archived from the original on 2014-09-27.
- "Slippery Tesla Model S triumphs in wind-tunnel shootout". Ecomento. 2014-05-30. Retrieved 2014-10-15.
- Seabaugh, Christian. "2016 Toyota Prius First Drive Review". MotorTrend. Retrieved 2015-11-18.
- Krivevski, Blagojce. "Xpeng Starts Delivery of P7 EV Sports Sedan". Retrieved 2020-06-28.
- "Audi A4" (Press release). Audi AG. Retrieved 2018-01-27.
- "Alfa Romeo at the 2016 Paris International Motor Show" (Press release). Retrieved 2018-01-29.
- "Specifications of the all-new BMW 3 Series Sedan, valid from 10/2018" (Press release). 2018-10-02. Archived from the original on 2019-03-17. Retrieved 2019-03-17.
- "Press Kit" (Press release). Tesla. Retrieved 2018-03-05.
- Disdale, James (2017-01-12). "New BMW 5 Series 2017 review". Auto Express. UK: Dennis Publishing Ltd. Retrieved 2018-01-25.
- Kable, Greg (2013-02-07). "Mercedes-Benz CLA180 cheats the wind". Autoweek. Crain Communications, Inc. Retrieved 2018-11-28.
- Some sources also claim this figure relates to a T87 model test not T77a"Tatra T600 Tatraplan". www.tatraplan.co.uk. Retrieved 2014-08-28.
- Ivan Margolius, 'Model Behaviour', Octane, February 2012, pp. 38-9
- Ivan Margolius & John G Henry, 'Tatra - The Legacy of Hans Ledwinka', Veloce, Dorchester, 2015, page 124
- Optimization and computational fluid dynamics, Gàbor Janiga, Springer, 2008, page 196
- "Cheating Wind - Aerodynamic Tech and Buyers Guide". europeancarweb.com. Retrieved 2008-03-13.
- "Tatra 77 aerodynamic car (czech)". Retrieved 2010-05-17.
- Winning the oil endgame: innovation for profits, jobs and security, Amory B. Lovins, Rocky Mountain Institute, 2004, page 53
- Brown, Aaron (2016-03-16). "Here's the story behind GM's revolutionary electric car from the 90s that disappeared". Business Insider. Insider Inc. Retrieved 2018-11-28.
- ZOELLTER, JUERGEN. "2014 Volkswagen XL1". Car and Driver. Hearst Communications, Inc. Retrieved 2017-12-25.
- "Original Avion Specifications - 1986". 100 mpg plus. 2007. Archived from the original on 2008-11-20.
vehicle set the 1986 Guinness World Record for fuel efficiency at 103.7 mpg
- Ihrig, Ron (2004-12-03). "Part 3: Production, Physics, Politics – Only the Strong Survive". Car Design News. German Design History. Archived from the original on 2011-01-11. Retrieved 2016-03-25.
- Volvo Car Corporation (2005-03-01). "Volvo ECC – the car that gave the world a preview of Volvo's future already back in 1992". media.volvocars.com (Press release). Retrieved 2017-12-15.
- "50 000 km avec une Citroën Ax diesel, mon avis d'utilisateur ainsi que son coût kilométrique réel". Generationsfutures.chez-alice.fr. Archived from the original on 2010-10-28. Retrieved 2010-12-07.
- "Opel 2002 Eco-Speedster". Retrieved 2015-09-30.
- Frank Giovinazzi (2005-06-14). "Mercedes Bionic Concept Car". Carbuyersnotebook.com. Archived from the original on 2011-06-13. Retrieved 2010-12-07.
- Motor Life-1958
- "Daihatsu UFE-III | Concept Cars". Diseno-art.com. Retrieved 2010-12-07.
- Annoy as little air as possible, Edison2 blog
- "Li-ion Motors Wave II". Li-ionmotors.com. Archived from the original on 2010-12-18. Retrieved 2010-12-07.
- "The Bizarre German Car That Was Ultra-Aerodynamic—And Totally Impractical". Wired. 2014-09-04. Retrieved 2014-10-15.
- Bargmann, Joe (2013-11-04). "Urbee 2, the 3D-Printed Car That Will Drive Across the Country". Popular Mechanics. Retrieved 2014-02-10.
- Ludvigsen, Karl. "Turbine Speed with Style". Hemmings Daily. Retrieved 2019-03-12.
- "D & H Enterprises, composites and fibreglass technology". Dhenterprises.com.au. Retrieved 2010-12-07.
- "TU Delft students build a car with the lowest air resistance in the world". Delft University of Technology. 2015-04-20. Retrieved 2015-04-29.
- "(a bicycle's lower frontal area is offset by a higher drag coefficient)". Lafn.org. Archived from the original on 2011-07-17. Retrieved 2011-06-28.
- "The Mayfield Company Homepage - Coefficient of Drag Tables and Curves". Mayfco.com. Retrieved 2010-12-07.
- "World record defended: The new A-Class Sedan: none is more aerodynamic" (Press release). Stuttgart, Germany: Daimler AG. 2018-07-23. Archived from the original on 2019-05-18. Retrieved 2019-05-18.
- Birch, Stuart (2013-03-18). "Mercedes' 2014 CLA is the new low-Cd king". SAE International. Archived from the original on 2018-02-01. Retrieved 2018-01-31.
- "Technical Specifications BMW 520d EfficientDynamics Edition, valid from 03/2017" (Press release). BMW. 2017-01-19. Retrieved 2018-01-28.
- "The All-new Renault Clio: The icon of a new generation fully revealed at Geneva Motor Show" (Press release). 2019-03-05. Retrieved 2019-10-21.
- "Specifications of the BMW X1, valid from 09/2018" (Press release). BMW Group. 2018-05-11. Retrieved 2019-03-29.
- "Renault Zoe Technical Specifications" (Press release). Renault Press. 2016-11-30. Archived from the original on 2018-02-19.
- Brooke, Lindsay (2016-01-11). "2017 Pacifica is first hybrid minivan, rides on all-new FCA platform - SAE International". articles.sae.org. SAE International. Retrieved 2019-01-23.
- "2019 Ram 1500 – More Space. More Storage. More Technology". www.ramtrucks.com. Archived from the original on 2018-01-16. Retrieved 2018-02-24.
- Santin, J. J.; Onder, C.H.; Bernard, J.; Isler, D.; Kobler, P.; Kolb, F.; Weidmann, N.; Guzzella, L. (2007). The world's most fuel efficient vehicle : design and development of Pac Car II. Zürich: vdf, Hochschulverlag AG and der ETH. p. 113. ISBN 978-3-7281-3134-8.
- "Power Consumption - IGSS'13". Retrieved 2015-09-30.
- McLeod, Mike (2013-05-26). "The Future of Automotive Design?". Design Engineering. Retrieved 2015-09-25.
- "Program: hpvplot (updated 11/12/07)". Ent.ohiou.edu. Archived from the original on 2008-12-16. Retrieved 2010-12-07.
- "Opel 2002 Eco-Speedster". Retrieved 2015-09-30.
- "350 MPGe at $20,000?". Retrieved 2015-09-30.
- Maroselli, Yves (2014-09-18). "Renault : la Vesta 2 plus performante en 1987 que l'Eolab en 2015". Le Point (in French). Retrieved 2018-02-08.
- "VW reveals 197bhp XL Sport". TopGear.com. Retrieved 2020-01-21.
- "Specs of Mercedes-Benz Bionic Car Concept (2005)". engineact. Archived from the original on 2014-04-24. Retrieved 2013-05-11.